In general, it is best to avoid resistance training of any kind that targets the thigh muscles. This means staying off the stair steppers and keeping resistance set to a minimum on ellipticals and treadmills. If one is walking in natural terrain, it is best to avoid paths that include a lot of uphill travel. The best workouts for thigh slimming involve only the body's own weight and many repetitions.
Walking is probably the best overall exercise one can choose to target the proper muscle groups and achieve thinner thighs. It is one of the most natural movements available and works each muscle group in the proper sequence. Walking is also good for toning and strengthening the core. Walking in natural terrain should avoid hills to limit the effect of gravity on resistance.
Those who are already in pretty good physical condition might wish to try running instead of walking in order to achieve a higher level of cardio exercise. This method works well as long as one works toward increasing distance rather than running faster. Sprinting works the same muscle groups, but tends to focus on building strength for short bursts while distance running is a program that focuses on repetitions.
The difference can be seen easily by looking at a distance or marathon runner side by side with a sprinter. The sprinter will have heavily muscled legs while the marathoner will have long, lean lines.
Dance provides another way to work the targeted muscles to achieve longer, more graceful lines. Many ballet movements are designed to target the areas of the upper legs where fat is most likely to accumulate and burn it away. At the same time, these moves are geared to providing long, graceful upper legs instead of heavily muscled ones. Dance instructors will normally be happy to demonstrate and teach these moves and provide coaching to help one obtain the best results.
Whether walking, running, or dancing, one must make stretching and cooling down an integral part of any workout plan that is geared toward helping obtain less bulky upper legs. Stretching will help to keep the muscles longer and more supple while preventing cramps or contractions that can give a bulkier appearance. One can use stretches learned from a dance instructor or one of several forms of yoga to achieve the proper stretch and cool down.
Diet is important. However, in the battle to get thinner thighs, dieting doesn't help in the least. One should control diet to lose overall body fat, but the key lies in choosing the best workout program and following it as a matter of routine in order to burn away the fat from the upper legs without adding bulky muscle in its place.
source : Get Thinner Thighs The Easy Way